The oral microbiome is the second largest microbial community in the human body. It contains more than 700 types of microorganisms, including more than 100 species of bacteria. Research indicates that the oral microbiome may play an important role in periodontal health, dental integrity, and oral wellness. Evidence suggests that some functional similarities may exist between gastrointestinal (GI) and oral microbiota. Certain systemic illnesses related to endocrine, metabolic, and immune systems have been linked to oral microbial equilibrium and some factors related to periodontal health.

A recently published review by Di Stefano and colleagues explored the potential link between GI and oral microbiota, periodontal health, and the inflammatory response. The authors describe the oral microbiome as an interconnection between the host immune system, microbes, and an extracellular polymeric matrix called the biofilm. This research indicates that agents in the oral microbiome may act as the primary line of defense against certain harmful bacteria, which may be due to their ability to release bactericidal molecules, such as hydrogen peroxide. They may also help prevent pathogenic adherence and lower the microenvironmental pH to help inhibit microbial growth.

The function of the inflammatory response in the body has been associated with both gut and oral microbiota. Chronic inflammation of the gingiva is often an initial occurrence in the progression of periodontal disease. Research indicates that a dysbiotic oral microbiome may influence a dysregulated inflammatory response. Certain pro-inflammatory cytokine clusters in the oral cavity, including interleukin (IL)-1, IL-6, and tumor necrosis factor may cause damage to periodontal ligaments and alveolar bone. Oral microbes may also influence certain aspects of gut health. Oral microorganisms have been shown to induce T-helper cells in the gut-associated lymphoid tissue in the presence of certain parameters related to colonic inflammation.

Research indicates that certain probiotics may help support the immune response, GI health, and oral wellness. Probiotics have been shown to help support microbial diversity, help suppress the production of certain pro-inflammatory cytokines, and help promote intestinal barrier function. They have also been shown in studies to help support subgingival microbial composition.

Improvements in certain biomarkers related to periodontitis have been observed in studies involving certain probiotics related to oral health. An animal study reported that certain strains of Lactobacillus and Bifidobacterium helped support a healthy response to inflammation in the oral cavity. They also exhibited activity against certain endodontic pathogens, including Streptococcus mutans, Candida albicans, and Enterococcus faecalis. Another animal study demonstrated the attenuation of periapical bone loss in the presence of oral probiotic supplementation.

A placebo-controlled, randomized, double-blind clinical trial investigated the potential efficacy of Lactobacillus rhamnosus SP1 in individuals with chronic periodontitis. When compared to a placebo, the treatment group was shown to experience reductions in periodontal disease. Other clinical studies have reported reductions in gingival inflammation in the presence of L. paracasei supplementation.

More research is needed, particularly for larger studies with longer durations within a clinical setting. Evidence suggests that probiotics may play a role in periodontal wellness. They may help support a healthy immune response, intestinal barrier integrity, and oral and GI microbial diversity.

By Dr. C Ambrose ND, MAT